compiler.h: Introduce caa_container_of_check_null

[urcu.git] / include / urcu / rculfhash.h

diff --git a/include/urcu/rculfhash.h b/include/urcu/rculfhash.h
index 29dd88f1f16b0ea320ffa82ef2ed0596c7aaba65..16f7d1cdaa433d47f72aecd31a20b3a99cc2a8fe 100644 (file)
--- a/include/urcu/rculfhash.h
+++ b/include/urcu/rculfhash.h
@@ -109,6 +109,16 @@ void cds_lfht_node_init(struct cds_lfht_node *node __attribute__((unused)))
 {
 }
 
+/*
+ * cds_lfht_node_init_deleted - initialize a hash table node to "removed" state
+ * @node: the node to initialize.
+ *
+ * Initialize the node such that cds_lfht_is_node_deleted() can be used
+ * on the node before it is added to a hash table.
+ */
+extern
+void cds_lfht_node_init_deleted(struct cds_lfht_node *node);
+
 /*
  * Hash table creation flags.
  */
@@ -237,16 +247,16 @@ struct cds_lfht *cds_lfht_new(unsigned long init_size,
  *
  * Return 0 on success, negative error value on error.
 
+ * Threads calling this API need to be registered RCU read-side threads.
+ *
  * Prior to liburcu 0.10:
- * - Threads calling this API need to be registered RCU read-side
- *   threads.
  * - cds_lfht_destroy should *not* be called from a RCU read-side
  *   critical section. It should *not* be called from a call_rcu thread
  *   context neither.
  *
  * Starting from liburcu 0.10, rculfhash implements its own worker
- * thread to handle resize operations, which removes RCU requirements on
- * cds_lfht_destroy.
+ * thread to handle resize operations, which removes the above RCU
+ * read-side critical section requirement on cds_lfht_destroy.
  */
 extern
 int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr);
@@ -534,24 +544,30 @@ void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size);
                cds_lfht_next_duplicate(ht, match, key, iter),          \
                        node = cds_lfht_iter_get_node(iter))
 
+#define cds_lfht_entry(ptr, type, member)                              \
+       ({                                                              \
+               caa_unqual_scalar_typeof(ptr) ___ptr = (ptr);           \
+               ___ptr ? caa_container_of(___ptr, type, member) : NULL; \
+       })
+
 #define cds_lfht_for_each_entry(ht, iter, pos, member)                 \
        for (cds_lfht_first(ht, iter),                                  \
-                       pos = caa_container_of(cds_lfht_iter_get_node(iter), \
-                                       __typeof__(*(pos)), member);    \
-               cds_lfht_iter_get_node(iter) != NULL;                   \
+                       pos = cds_lfht_entry(cds_lfht_iter_get_node(iter), \
+                               __typeof__(*(pos)), member);            \
+               pos != NULL;                                            \
                cds_lfht_next(ht, iter),                                \
-                       pos = caa_container_of(cds_lfht_iter_get_node(iter), \
-                                       __typeof__(*(pos)), member))
+                       pos = cds_lfht_entry(cds_lfht_iter_get_node(iter), \
+                               __typeof__(*(pos)), member))
 
 #define cds_lfht_for_each_entry_duplicate(ht, hash, match, key,                \
                                iter, pos, member)                      \
        for (cds_lfht_lookup(ht, hash, match, key, iter),               \
-                       pos = caa_container_of(cds_lfht_iter_get_node(iter), \
-                                       __typeof__(*(pos)), member);    \
-               cds_lfht_iter_get_node(iter) != NULL;                   \
+                       pos = cds_lfht_entry(cds_lfht_iter_get_node(iter), \
+                               __typeof__(*(pos)), member);            \
+               pos != NULL;                                            \
                cds_lfht_next_duplicate(ht, match, key, iter),          \
-                       pos = caa_container_of(cds_lfht_iter_get_node(iter), \
-                                       __typeof__(*(pos)), member))
+                       pos = cds_lfht_entry(cds_lfht_iter_get_node(iter), \
+                               __typeof__(*(pos)), member))
 
 #ifdef __cplusplus
 }